Telephone-exchange system.



G. BABCOCK.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED FEB. 11. 1910 Patented June 6,1916.

2 SHEETS-SHEET 2- Inv ET nr' Barr un BElhED DK H AUETHE 5 GARRISONBABCOCK OF ROCHESTER, YORK.

TELEPHONE-EXCHANGE SYSTEM.

Specification of Letters latent.

PatentedJune 6, 1916.

Application filed February 17, 1910. Serial No. 544,429.

To all whom i. may concern."

Be it known that I, GARRISON BABoooK, a citizen of the United States, residing at Rochester, in the county of Monroe and State of New York, have invented a certain new and useful Improvement in Telephone- Exchange Systems, of which the following is. a full, clear, concise, and exact description, reference being bad to the accompanying drawings, forming a part thereof.

My invention relates to service meters for telephone exchange systems, and has reference particularly to that class of service meters in which the metering mechanism is located at the substations.

It is an objectof my invention to provide a meter of the class -referred to of such a nature that the meter is under the joint control of the subscriber and of the apparatus located at the exchange which apparatus is controlled by the called subscriber in answering the call.

My invention refers particularly to such a combination of parts thatthe operation of registering a call initiated at any substation is accomplished by means of the operation at such substation of the mechanism.ordinarily .used in calling the central exchange.

After connection has been made by the operator at the exchange with the calling line and such connection has been extendedto the called line, response on the part of the called subscriber causes operation of relay mechanism associated with the cord, circuit employed in making the connection in such a manner as to reverse the polarity of the current supplied to the answering end of I the cord circuit and in this manner apparatus is actuated at the calling substation which apparatus by its operation serves to reset the register ready for registering another call.

- In carrying out my invention I prefer to employ at the substation a polarized relay which is responsive to a reversal in current direction, as a result of which the resetting magnet is actuated when the polarized relay is operated. After having been properly reset to be actuated the meter may be operated either by the mechanical operation of the switch hook or may be electrically operated by a circuit closed by the motion of the switch hook-from its talking to its normal position. i V

.1 its talking condition while the apparatus at position. The contact'15 is connected by a '18 is connected by a wire 20 with the pri-.

The several drawings illustrating my in vention are as follows: f

Figure 1 is a diagrammatic drawing showing the telephone system complete with the apparatus at one ofthe substations in the other substation is shown in its normal or resting condition. Fig. 2 shows a modified form of apparatus that may be used in connection with the meter armature to control the circuit of its magnet and also to hold the armature in its attracted position. Fig. 3 is a detail view of a construction that may be employed in connection with the polarized relay to provide against accidental opening of the contact adapted to be closed by such relay.-

Similar numerals refer ,to similar parts throughout the several views.

In Fig. 1 of the accompanying drawings illustrating my invention, the substation A is connected by line wires 1 and 2 with they exchange',:the line circuit there terminating in the tip and sleeve springs 3 and 4 respectively of the line jack J. The springs 3 and 4 normally make contact with the contact springs 5 and 6 respectively. The spring 5 is connected with the winding of the line relay 7, the other terminal of which is connected by wire 8 with the negative pole of the battery B. The spring 6 is conbattery B.

At the substation the line wire 1 is connected by a wire 10 with the pivotal point of a polarized armature 11.0f the combined induction coil and magnet 12, the core 13 of which is extended to attract the polarized ends of the armature 11. The armature 11 carries a spring 14 adaptedto engage a contact 15 when the armature is in its normal wire 16 with a contact 17 adapted to engage aspring 18 when the switch hook 19 is in its raised or calling position. The spring mary winding of the induction coil 12' the other terminal of which is connected bywire 21 with the transmitter T,'tlie otherterminal of which is connected directly to 105 theline wire 2. The secondary winding of the induction coil 12 is connected directly with the receiver R, asindicated.

The register mechanism 22 1s a nectedby wire 9 with the positive'pole of 7 dapted to be operated by a lever 23 pivoted at 24 b means of a pawl 25 pivoted at 26 to suc lever. The right-hand end of the lever is extended beyond the pivot 24 to be engaged by 'a pawl 27 pivoted at 28 to the left-hand end of the switch hook 19,'which is pivotally supported at 29. The pawl 27 is so conformed that when the switch hook is in its lower or normal position the shoulder formed on the lower end of such pawl rests over the right-hand end of the lever 23, and as the switch hook 19 is raised while being moved from its normal position the spring usually provided to cause this operation, and not" spring 23 which is of sufficient tension to hold the lever 23 and pawl 25 in their upper position but, is not strong enough however, to operate the register mechanism 22. The lever 23 also serves as a polarized armature for the resetting magnet 31 of the registering mechanism, as a result of which when the magnet 31 is properly energized the lever 23 is moved forcibly downward thus resetting the pawl 25 in position to subsequently operate the registering mechanism. This motion of the lever 23 releases the spring 32 which is comparatively stiff and permits it to engage the contact 31 carried by the contact spring 33.

The springs 32 and 33 carry at their upper ends rollers 32 and 33 disposed side by side and opposite the beveled left hand end of the lever 23. The centers of the rollers 32 and 33 are so disposed that when the lever 23 is x in its upper or actuated position, the centers of such rollers lie practically in a continuation of the lower side of such lever and the tension exerted by the springs 32 and 33 upon the end of the lever 23 does not, therefore tend to throw the lever in one direction or the other. When, however, the lever 23 is attracted to itsresetting position, the roller 32' being smaller than the roller 33, is entirely disengaged from, the left hand end of the lever 23 and thus the spring 32 is permitted to engage the contact 31 as a result of which the tension of the spring 32 is add ed to the tension of the spring 33 and the combined efi'ort is exerted upon the left hand end of the lever 23 and upon the beveled surface formed thereon, as a result of which at this time the roller 33 serves to lock the lever 23 in its reset position and the spring 32 and the contact 31 are held positively in engagement.

The resetting magnet 31 is connected be tween the line wire 1 and the wire 16, as indicated, and the contact springs 32 and 33 are connected to the terminals of the resetting magnet, as a result of which when the lever 23 has been moved downward to its resettin position the closure of the contacts 32 and 31 establishes a short circuit between the terminals of the resetting magnet, andfurther operation of such magnet is therefore prevented until the lever 23 is again moved upward mechanically by means of the switch hook 19. A-further result accomplished by the closure of the contacts 32 and 31 is that the impedance of the reseting magnet 31 at the calling substation is removed from the line circuit during talking.

The switchhook 19 is so disposed relatively to the contacts 17 and 18 that when in, its depressed position which is its normal position under the weight of the receiver B, it engages a block of insulation 18 carried by the spring-18, and thus separates the contacts 17 and 18 and interrupts the circuit through the primary winding of the induc tion coil 12, which primary winding is also effective in energizing the core 13 to cause operation of the armature 11. The primary winding referred to is so wound that cur rent in one direction, which, in the embodiment herein shown,'is assumed to be in a direction entering the winding from the wire 21, will attract the armature 11 in a manner to close and maintain such armature in its normal position to close the contacts 14 and 15, which closure establishes a shunt or short circuit through the wires 10 and. 16 between the terminals of the resetting magnet 31.

Assuming that the receiver R has been re moved from the switch hook 19, as shown at the substation A, the register 22 is actuated and the contacts 17 and 18 are closed, and thus in a manner well known in the art, the line relay 7 is energized by the pulling up of its armature 34 against the contact 35, and a circuit is closed between the wires 8 and 9 through the line lamp 36 to signal the operator at the exchange that a connection is desired. The current in the line at this time flows through thetransmitter T, the primary winding of the induction coil 12 and through wires 16 and 10, and by the motion of the switch hook 19 to its raised position the lever 23 and pawl 25 have been moved to a position to operate the register mechanism 22. This condition continues until the'direction of current floiv through the instrumentalities referred to is reversed, at which time the opposite pole of the arniature 11 is attracted, as a result of which the line current now flows through the reset ting magnet 31 as well as through the other instrumentalities described. This results in the attraction of the lever 23 and the resetting of the registering mechanism 22. lVhcn the lever 23 reaches its lower position it closes the contacts 32 and 31, thus short-circuiting the resetting magnet 31, and the lever remains in this position, as a result of the action of the spring 32 and 33 and the roller 33 described above. The reversal of current flow inthe line circuit is accom plished as follows:

The cord circuit herein shown consists of two strands 37, 38, extending from the tip and sleeve 39,40 of the; answering plug P to the tip and sleeve 41 and 42 of the calling plug P, respectively. The strands .37 and 38 have connected in them the listening key 43 and the ringing key 44, and these strands are interrupted conductively, although continuous inductively by the condensers 45, 46, in a manner well known in the art. An operators set 47 is provided in the usual manner, such set being connected with the listening key 43.

The battery B connected by the wires 8 and '48 with one terminal of the winding of the tip supervisory relay 49, the other terminal of which is connected by wire 50 with the answering end of the strand 37. The same terminal of the battery B is also connected by wire 51 with one terminal of the winding of the tip supervisory relay 52, the other terminal of which is connected with the calling end of the strand 37 by wire 53. The-positive pole of the battery B is connected by wire 54 with one terminal of the winding of the sleeve supervisory relay 55, the other terminal of which is connected by wire 56 with the calling end of the strand 38. The same pole of the battery B is also connected by wires 54 and 57 with the back contact 58 of the armature 59 of the relay 55.

The armature 59 is connected by wire (30 with one terminal of the winding of the sleeve supervisory relay 61, the other terminal of which is connected by the wire 62 with the answering end of the sleeve strand 38. A generator Gr is provided, and has its field winding 63 connected by wires 64 and 65 directly with the terminals of the battery B. The positive and negative brushes (3G and 67 of the generator are connected respectively by wires (38 and ()9 with the positive pole of the battery B, and the front contact 70 of the armature 59.

The armatures 71 and 72 of the supervisory relays 49 and 52 are normally in engagement with their back contacts 73 and 74, which are connected with the supervisory lamps 75 and 76 respectively, the other terminals of these lamps being connected together by the wire 9 to the positive pole of the battery B. The armatures 71 and 72 are connected together by the wire 77, and are also connected by the wire 78 with the spring contact 79 of the plug seat switch S, the other member 80 of which is connected by has its negative terminal same direction as it was previously supplied through the springs 5 and 6, as a result of which no actuation of the armature 11.

occurs, since the core 13 is magnetized in the same direction. This condition con tinues until the'called subscriber, after having been properly connected by the insertion of the calling plug P in the jack J,

and operation of the signaling mechanism,-

not shown, at the called substation, responds by removing his receiver from his switch hook. The signaling mechanism at the substation is not shown here in detail since it forms no part of this invention. WVhen the called subscriber removes his receiver from the switch hook he closes a cir cuit through the substation apparatus, thus causing the energization of the .relay 55. This results in pulling up the armature 59 and interrupting the circuit from the positive pole of the battery B through wires 57 and 60 to the winding of the supervisory relay 61, and closing a path between the negative brush of the generator Gi'through wire 69, contact 70, armature 59, and wire 60 to the same terminal of the relay 61. The potential developed by the generator G should be approximately twice the potential of the battery B, and as a result current is caused to flow through the battery Bin opposition to its voltage, and the resultant voltage impressed upon the strands 37 and 38' is of about the same value as the voltage of the battery B but in a reverse direction. The generator Gr is especially constructed so as to supply direct noiseless current to the substation circuit which is adapted for talking purposes, and by its flow through the primary winding of the induction coil 12 it reverses-the polarity of the core 13, thus rotating the armature 11 around to the left upon its pivot 11 and separating the contacts 14 and 15, and, since the contacts 32 and 31 are open and the contacts 17 and 18 are closed, the resetting magnet 31 is energized, thus setting the register 22, at the of current sent through the primary wind- 1 ing. of the induction coil at the called station, it follows that although the meter mechanism at the called substation has been actuated by the removal of the receiver there located, and that therefore the corresponding contacts 32 and 31 are separated, the associated resetting winding is still inoperative as a result of the shunt closed by such contacts 14and 15 as a result of which the impedance of the resetting magnet at the called station is removed from the line circuit during a conversation.

From thecircuits above described it will be noticed that the supervisory lamps 75 and 76 are lighted when the apparatus at the corresponding substations is returned to its normal position by hanging the receivers upon the hooks and that fiowof current through the supervisory lamps 75 and 76 is interrupted by the opening of the plug seat switch S when the calling plug P is returned to its normal position. 7

The lever 23 at the substation A is polarized in order that if the contacts 14 and 15 become accidentally separated the resetting magnet 31 may not be actuated byan initial flow of, current therethrough before the contacts 14 and 15 are closed by the energization of the core 13. The polarization of the lever 23 is in such a direction that it will only respond to a current flow through the.

direction of energization of the core 13 whether the contacts 14 and 15 are closed or not. v

From the above it will appear that if the called subscriber does not respond, although the registering mechanism at the calling substation has been actuated, the calling subscriber is not improperly charged because when he makes the next call, it will effect no actuation of the registering mechanism, inasmuch as it was not reset during the preceding calling operation. In other Words, by my system, although a call may .be registered, when the calledvpartyis not available, still the charged call is in effect credited since no advance of the registering mechanism is made for the next call which may be responded to by the called subscriber.

The arrangement of the meter operating mechanism at the substation D is identical with that shown and described for the substationA, theonly difierence. being that in connection with the substation D the lever 23 is shown in its lower position and the switch hook 19 is shown in its normal position supporting the receiverR In Fig. 2 a modified form of substation apparatus adapted to operate the registering mechanism is shown which differs from that shown in Fig. 1 in that an operating magnet 85 is provided for actuating the registering mechanism in place of mechanically actuating the register by means of the switch hook 19. The winding of the magnet 85 is connected between theline conductor 1 and the spring 18 adapted to be engaged by the spring 18 when the hook switch is in its norlever is in its set position the spring 86 engages the roller 88 but the engagement between the' springs 86 and 87 serves to lift the spring 87 from engagement with the roller ,89. When, however, the lever 23 is moved downward at its right hand end the roller 89 comes into engagement with the spring 87 while the roller 88 is moved from engagement with 'the spring 86 thus allowing the spring 86 to spring away to the left from engagement ,with the spring 87 and open the circuit through the energizing winding of the magnet 85. The conformation of the upper'end of the spring 87 serves at this time to retain the lever 23 in the position to which it has been moved by the magnet 85. In this modified form of apparatus the springs 32 and 33 are conformed at their upper ends to engage the rollers 32' and 33' which are carried by the left hand end of the lever 23. The coijperation of the springs-32 and 33 and the rollers 32' and33 is similar to that already shown and described in connection with Fig. 1, the spring 33 serving, when the lever 23 ismoved downward at its left hand end, to lock the lever in such position until it is positively operated by means of the magnet 85. In this modification the transmitter and primary winding of the induction coil 12 are included between the windin 31 and the spring 17 of the hook switch instead of be ing included between the line conductor 2 and the spring 18 as shown in Fig. 1. A

7 means at the exchange for setting and shunting such meter by reversing. the direction'of erly actuated to effect such result. In this modification the levers 14 and 14 are pivothave considerable more motion than is im-.

parted to the right hand end of the lever 14. The lever 14 is arranged so that in one posi-,

tion it rests against a stop 14 and in its other position it rests against the contact 15. The contact 15 and the stops 14 14 and 14 are so disposed relatively to the pivot 14 that when the lever 14 is moved from one stop 14 to the other stop 14 or vice versa, the spring 14 passes the pivotal point 14 and serves to forcibly move the other lever 14 from its previous position to its alternate position as the case may be..

Thus the lever 14 isheld positively in either of its positions by means of the spring 14 and any vibration of the armature 11 will not result in'throwing the lever 14 either from its stop 14 into engagement with the contact 15 or away from the contact when it ought to be in engagement therewith.

While I have shown my invention in the particular embodiments herein described, 'I do not, however, limit myself to this construction, but desire to claim any equivalent that may suggest itself to those skilled in the art.

What-I claim is:

1. In a telephone exchange system, the combination of a main exchange, telephone lines extending from substations to such ex-.

change, a meter at one of such substations, means at the exchange for setting and shunting such meter by reversing the direction of current flow through the associated line upon a subscribers answering a call, and means for actuating the meter.

2. In a telephone exchange system, the combination of a main exchange, telephone lines extending from substations to such exchange, a meter at one of such substations,

current flow through the associated line by response of the called subscriber upon asubscribers answering a call, and means for actuating the meter.

V 3. In a telephone exchange system, the combinationof a main exchange, telephone lines extending from substations to such exchange, a meter adapted to be actuated by mechanical operation located at one of such substations, means at the exchange for setting andshunting such meter by reversing the direction of current flow through the associated line upon a subscribers answering a call, and means for actuating the meter. I

4. In a telephone exchange system, the combination of a main exchange, telephone lines extending from substations to such exchange, a self-shunting meter, means for automatically operating it upon the act of taking for use of the talking apparatus at the substation, and means "at the exchange for setting such meter by reversing the direction of current flow through the associated line without interruption of use of the talking apparatus. 1 v i 5. In a te e hone exchange system, the

combination 0 a main exchange, telephone lines extending from substations to such exchange, a meter adapted to be mechanically operated by the switch hook in calling, means at the exchange for setting such meter by reversing the direction of current flow through the associated line and operating connection between the meter and switch hook.

6, In a teleiphone exchange system, the combination 0 a main exchange, telephone lines extending from substations tosuch exchange, a call register meter at one of such substations, two sources of current connected in opposition, means for connecting one of such sources to a line in response to a call, and means for connecting the second. source through the first source toreverse the direction of current flow in the line to set the meter and means for operating the latter for registering a call.

7. In a telephone exchange system, the combination of a main exchange, telephone lines extending from substationsto such exchange, a meter at one of such substations,-

ing the second source through the first source to reverse the direction of current flow 1n the line to set the meter and means for operating the latter for registering a call.

8. In a telephone exchange system, the

combination of a main exchange, telephone lines extending from substations to such exchange, a meter at one of such substations means for operating it, a source of current at the exchange for supplying signaling current to the lines, a resetting magnet for the meter, a controlling magnet connected .to

the line circuit and adapted by its operation to cause the energization of the resetting magnet, application of signaling current to v i a calling line traversing the controlling magnet 1n an lnoperatlye direction, and means for reversing the direction of current lines extending from substations to such ex change, a meter at one of such substations, a source of current at'the exchange for supplying signaling ourrent to the lines, a resetting magnet for the meter adapted to be operated by current flowing over the line circuit, apolarized relay connected with the line circuit and adapted to be actuated by current flow through the line in but one direction, a shunt circuit normally closed around the terminals of the resetting magnet by such relay, means for supplying signaling current to such line in response to a call in an inoperative direction relatively to such relay, a second source of current of higher otential than the first source, and means or connecting such second source to the line circuit through and in opposition to the first source to operate such relay, the operation of such relay serving to open the shunt circuit and cause actuation of the resetting magnet and means for operating the meter to register a call.

10. In a telephone exchange, system, the combination of a main exchange, telephone lines extending from substations to such ex change, a meter at one of such substations, a source of current at the exchange for sup-- plying signaling current to the lines, a resetting magnet for the meter adapted to be operated by current flowing over the line circuit, a polarized relayrconnected with the line circult and adapted to be actuated by current flow through the line in but one direction, a shunt circuit normally closed around the terminals of the resetting magnet by such relay, means for supplying signaling current to such line in response to a call in an inoperative direction relatively to such relay, a second source of current of higher potential than the first source, and means automatically operated by the response of the called subscriberfor connecting such second source to the line circuit through and in opposition to such first source to operate such relay, the operation ofsuch relayserving to open the shunt circuit and cause the actuation of the resetting magnet and means for operating the meter to register a call.

11. Inc, telephone exchange system, the combination of a main exchange, telephone lines extending from substations to such exchange, a meter at one of such substations, a

source of current at the exchange for sup plying current to such line in an inoperative directlon relatively to the meter, a second source of current of higher potential than the first source, and means for connecting such second source to the line through and in opposition to such first source to reset the meter and means for operating the meter to register a call.

12. In a telephone exchange system, the combination of a main exchange, telephone lines extending from substations to such exchange, a meter at one of such substations, a source of current at the exchange for supplying signaling current to the lines, a resetting magnet for the meter adapted to be operated by current flowing over the line circuit, a polarized relay connected with the line circuit and adapted to be actuated by current flow through the line in but one direction, a shunt circuit normally closed around the terminals of the resetting magnet by such relay, mechanism associated with the switch hook at the substation to actuate the meter, such switch hook serving when in its normal position to interrupt the circuit through such relay, means for supplying sig-, naling current to such line in response to a call in an inoperative direction relatively to such [rela and means for reversing the direction 0 current flow in the line to operate such relay, the operation of such a relay serving to open the shunt circuit and cause actuation of the resetting magnet.

13. In a telephone exchange system, the combination of a main exchange, telephone lines extending from substations'to such exchange, a meter at one of such substations, a source of current at the exchange for supplymg slgnaling current to the lines, a resetting magnet for the meter adapted to be operated by current flowing over the line circuit, a polarized relay connected with the line circuit and adapted to be actuated by current flow through the line in but one direction, a shunt circuit normally closed around the terminals of the resetting magnet by such relay, mechanism associated with the switch hook at the substation to actuate the meter, such switch hook serving when in 1ts normal position to interrupt the circuit through such relay, means for supplying signallng current to such line in response to a call in an lnoperative direction relatively to such relay, a second source of current of higher potential than the first source, and means for connecting such second source to the line cuit, a polarized relay connected with" the line circuit and adapted to be actuated by current flow through the line in but one direction, a shunt circuit normally closed around the terminals of'the resetting magnet by such relay, means for supplying signaling current to such line in response to a call in an inoperative direction relatively to such relay, means for reversing the direction of current flow in the line to operate such relay, the operation of such relay serving to open the shunt circuit and cause actuation of the resetting magnet, a second shunt circuit about the terminals of the resetting magnet adapted to be closed by the resettingof the meter and an operating connection between the meter and switch hook of the subscribers substation apparatus. 1

.15. In a telephone exchange system, the combination of a main exchange, telephone lines extending from substations to such exchange, a meter at one of such substations, a source of current at the exchange for supplying signaling current to the lines, a resetting magnet for the meter adapted to be operated by current flowing over the line circuit, a polarized'relay connected with the line circuit and adapted to be actuated by current flow through the line in but one direction, a shunt circuit normally closed around the terminals of the resetting magnet by such relay, mechanism associated with the switch hook at the substation to actuate the meter, such switch hook serving when in its normal position to interrupt the circuit for connecting such second source to the line.

circuit through and in opposition to the first source to operate such relay, the operation of such relay serving to open the shunt circuit and cause actuation of the resetting magnet and a second shunt circuit about the terminals ofthe resetting magnet adapted to be closed by the resetting of the meter.

16. In a telephone exchange system, the combination of a main exchange, telephone lines extending from substations to such ex-' change,a meter at one of such substations, a

battery at the exchange adapted to send signaling current through a line when in calling conditionfsuch current also traversing the meter controlling mechanism without effecting its operation, switching mechanism at the-exchange for supplying talking current to the calling line through the meter controlling mechanism without operating the same, and a relay at the exchange operated by the response of a called subscriber, the operation of a such relay serving to supply current through the switching means in a reverse direction to the line to cause the resetting of the meterand means for o'perating the meter to record a call.-

17. In a telephone exchange system, the

combination of a main exchange, telephone lines extending from substations to such exchange, a meter at one of such substations, a source of' current at the exchange for supplying signaling current to the lines, a re setting magnet for the meter adapted to be operated by current flowing over the line circuit, a polarized relay connected with the line circuit and adapted to be actuated by current flow through the line in but one direction, a, shunt circuit normally closed around the terminalsof the resetting magnet by such relay, mechanism associated with the switch hook at the substation to actuate the meter, such switch hook serving when in its such second source to the line circuit through and in opposition to the first source to operate the polarlzed relay, the'operation of such polarized relay serving to open the shunt circuit and cause actuation of the resetting magnet, and a second shunt circuit about the terminals of the resetting magnet adapted to be closed by the resetting of the meter.

18; In a telephone system, a self-shunting substation meter having a member movablein one direction for'operating it, means for actuating said member in said direction upon use of the substation apparatus to initiate a call and means for electrically resetting said member in the opposite direction.

19. In a telephone system, a central exchange, a self-shunting substation meter comprising registering mechanism and a member movable in one direction for operating it upon use of the substation apparatus to initiate a call and means for moving said member in the opposite direction operated electrically from the exchange.

20. In a telephone system, a' central exchange, a substation meter comprising registering mechanism and a member movable in one direction, for operating it upon use of the substation apparatus in calling the exchange, a line circuit extending from the substation to the exchange and means operated by a reversal of current in said circuit resulting from the response-of the called subscriber for moving sai'd'operating member in the opposite direction.

21. In a telephone system, a substation meter comprising the combination of regis- I tering mechanism, .a line circuit extending from the substation to an exchange, a resetting magnet for the meter, and a controlling magnet, such controlling magnet adapted to be operated by a reversal of current therethrough resulting from the response of the called subscriber and means for operating the meter.

22. In a telephone system, a substation meter comprising the combination of regis-' tering mechanism, a resetting magnet for y the meter, and a controlling magnet, such resetting magnet normally rendered inoperative by the controlling magnet and placed in condition to operate by operation of the controlling magnet and means for operating the meter.

23. In a telephone system, a substation meter comprising .the combination of registering mechanism, a resetting magnet. for said mechanism, a circuit therefor and a second magnet controlling the energization of the resetting magnet, such resetting magnet circuit belng normally inoperative and adapted to be placed in operative condition by the conjointoperation of the controlling magnet and the movement ofthe substation switch hook to its calling position.

24. In a telephone system, a substation meter comprising the combination of registering mechanism, a resetting magnet for the meter, and a controlling magnet, such, resetting magnet normally rendered inoperative by the controlling magnet and the substation switch hook, and placed in condition to operate by motion of theswitch hook to a, calling position andby operation of the controlling magnet and means for operating the meter. v25. In a telephone system, a substation meter comprising the combination of registering mechanism, a resetting-magnet for the meter, and a controlling magnet, such resetting magnet normally inoperative and adapted to be placed in operative condition by motion of the substation switch hook to its calling position, motion of the switch hook serving to actuate the meter.

26. In a telephone system, a substation meter comprising the combination of registering mechanism, a resetting magnet for the meter, and a controlling magnet, such.

resetting magnet normally rendered inoperative by the controlling magnet and the substation switch hook and placed in condition to operate by motion of the switch hook to a calling position and by operation of the controlling magnet, motion of the switch hook serving to actuate the meter.

27. In a meter adapted for use at a telephone substation, the combination of registering mechanism, an electromagnet for setting the register, andmeans controlled by the setting operation for closing a shunt between the terminals of the resetting magnet.

28. In a meter-adapted for use at a telephone substation, the combination of registering mechanism, an electromagnet for resetting the registering. mechanism, and

switch springs controlled by the resetting. 'magnet and adapted to close a shunt between the terminals same is operated.

29. In a meter adapted for use at a tele phone substation, the combinationof registering mechanism, an electromagnet for resetting the registering mechanism, and switch springs controlled by the resetting magnet and adapted to close a shunt be tween the terminals, of such magnet when the same is operated,-such switch springs adapted to retain the registering mechanism in its reset position. i

30. In a telephone exchange system, the combination of a main exchange, telephone lines extending from substations to such exchange, meters associated' with the telephone lines at the substations, a resetting magnet associated with each meter and adapted .to be operated by current in the line circuit, and means for removing. the impedance of the resetting magnet at the calling and called substations from the line during a conversation.

of such magnet when the 31. In a telephone exchange system, thesubstation serving to actuate the resetting magnet and close a shunt circuit between its terminals, and, thepolarized relay at the called station serving by remaining in its normal position during a conversation to remove from the line circuit the impedance of the associated resetting magnet.

In witness whereof, I hereunto subscribe my name this 10th day of February, A. D. 1910.

GARRISON Bassoon.

lVitnesses:

ALBERT C. BELL, Bonner F. BRACKE- 

